Analysis of collagen-interacting proteins in patients with incisional hernias

Outcomes of complex abdominal wall reconstruction in patients with connective tissue disorders: a single center experience

INTRODUCTION

Individuals diagnosed with connective tissue disorders (CTD) are known to be predisposed to incisional hernia formation. However, there is a scarcity of data on outcomes for these patients undergoing hernia repair. We sought to describe our outcomes in performing abdominal wall reconstructions in these complex patients.

METHODS

Adult patients with CTD undergoing open, elective, posterior component separation with permanent synthetic mesh at our institution from January 2018 to October 2022 were queried from a prospectively collected database in the Abdominal Core Health Quality Collaborative. We evaluated 30-day wound morbidity, perioperative complications, long-term hernia recurrence, and patient-reported quality of life.

RESULTS

Twelve patients were identified. Connective tissue disorders included Marfan's n = 7 (58.3%), Loeys-Dietz syndrome n = 2 (16.7%), Systemic Lupus Erythematosus n = 2 (16.7%), and Scleroderma n = 1 (8.3%). Prior incisions included three midline laparotomies and nine thoracoabdominal, mean hernia width measured 14 cm, and 9 were recurrent hernias. Surgical site occurrences (SSOs) were observed in 25% of cases, and 16.7% necessitated procedural intervention. All twelve patients were available for long-term follow-up, with a mean of 34 (12-62) months. There were no instances of reoperation or mesh excision related to the TAR procedure. One patient developed a recurrence after having his mesh violated for repair of a new visceral aneurysm. Mean HerQLes scores at 1 year were 70 and 89 at ≥ 2 years; Mean scaled PROMIS scores were 30.7 at 1 year and 36.3 at ≥ 2 years.

CONCLUSION

Ventral hernia repair with TAR is feasible in patients with connective tissue disorder and can be a suitable alternative in patients with large complex hernias.

Genetic and biologic risk factors associated with hernia formation: A review

BACKGROUND

This systematic review aims to identify genetic and biologic markers associated with abdominal hernia formation.

METHODS

Following PRIMSA-guidelines, we searched PubMed, MEDLINE, Embase, Scopus, and COCHRANE databases.

RESULTS

Of 5946 studies, 65 were selected, excluding parastomal hernias due to insufficient data. For inguinal hernias, five studies unveiled 92 susceptible loci across 66 genes, predominantly linked to immune responses. Eleven studies observed elevated MMP-2 levels, with seven highlighting greater MMP-2 in direct compared to indirect inguinal hernias. One incisional hernia study identified unique gene-expression profiles in 174 genes associated with inflammation and cell-adhesion. In hiatal hernias, several genetic risk loci were identified. For all hernia categories, type I/III collagen ratios diminished.

CONCLUSIONS

Biological markers in inguinal hernias appears consistent. Yet, the genetic predisposition in incisional hernias remains elusive. Further research to elucidate these genetic and biological intricacies can pave the way for more individualized patient care.

Surgical treatment strategy for recurrent parastomal hernia: Experiences from 17 cases

Purpose

This study aimed to investigate the surgical treatment strategy of recurrent parastomal hernia (PH) and show its safety, feasibility, and outcomes at a mid-term follow-up.

Methods

A total of 17 cases of recurrent PH treated at our hospital between January 2016 and October 2021 were included in this retrospective analysis. Patient characteristics were recorded, and the classification of PH, operative time, intraoperative blood loss, hernia repair techniques, follow-up times, complications, as well as recurrence were compared and analyzed.

Results

Altogether, 17 patients with recurrent PH underwent successful hernia repair via surgical treatment at The First Affiliated Hospital of Shandong First Medical University and Shandong University Qilu Hospital. No recurrence or severe complications were noted during follow-ups (mean 32.8 ± 3.77 [range 3–68] months).

Conclusions

For recurrent PH, selecting a suitable repair approach based on intraperitoneal conditions such as infection, abdominal adhesions, or the length of the bowel loop, can help in achieving better therapeutic results. The lap-redo + Sugarbaker technique is worth recommending when the appropriate conditions are met.

Recommendations on Postoperative Activities After Abdominal Operations and Incisional Hernia Repair-A National and International Survey

Background: There is no conclusive data on postoperative recommendations after abdominal and hernia surgery, and there is significant variation in the literature on that question. Thus, this study evaluates the status quo of recommendations of postoperative activity restriction after abdominal surgery. Materials and Methods: A national (German) and international survey of general surgeons on postoperative recommendations after abdominal and hernia surgery was pooled and analyzed. Results: A total of 74.6% recommended postoperative reduced activity for 2 weeks or less after laparoscopy. For midline laparotomy, 48.8% considered a reduced activity of 4 weeks or less to be sufficient. A majority from the national survey recommended more than 4 weeks instead (60.2%), whereas only 31.5% from the international survey did so (p = 0.000). In the pooled analysis, 258 of 450 (57.3%) rated 4 weeks or less suitable. However, the recommendations differed significantly between the surveys (4 weeks or less: a national survey, 47.1% vs. international survey, 64.6%; p = 0.000). Conclusion: There was substantial variation in the given recommendations. However, we found no evidence against immediate mobilization, reduced physical activity, and lifting for up to 2 weeks after laparoscopic surgery and for up to 4 weeks after open abdominal surgery and open incisional/ventral hernia repair in uncomplicated and standard cases. There might be individual and socioeconomic benefits to allow patients to return to their whole personal level of activity and work without putting them at risk of complications. Due to lack of evidence, both retrospective and prospective, controlled studies are in need to develop reliable recommendations.

Lack of Standardized Advice on Physical Strain Following Abdominal Surgery

BACKGROUND

In Germany as elsewhere, standardized recommendations are lacking on the avoidance of physical exertion to protect the abdom - inal wall in patients who have recently undergone abdominal surgery. It is unclear how much stress the abdominal wall can withstand and how long the patient should be exempted from work. The goal of this review is to determine whether there are any standardized, evidence-based recommendations for postoperative care from which valid recommendations for Germany can be derived.

METHODS

We systematically searched the literature for evidence-based recommendations on exertion avoidance after abdominal surgery, as well as for information on the extent to which postoperative abdominal wall stress contributes to incisional hernia formation. We then created a questionnaire on recommendation practices and sent it to all of the chiefs of general and visceral surgery services that were listed in the German hospital registry (1078 chiefs of service as of June 2016).

RESULTS

All 16 of the included studies on postoperative exertion avoidance contained low-level evidence that could only be used to formulate weak recommendations ("can," rather than "should" or "must"). Some 50 000 incisional hernia repair procedures are performed in Germany each year, with a reported incidence of 12.8% in the first two years after surgery. The scientifically documented risk factors for incisional herniation are related to techniques of wound closure, the suture materials used, wound infections, and the patient risk profile. From the biological point of view, the abdominal wall regains full, normal resistance to exertional stress 30 days after a laparotomy with uncomplicated healing. Most incisional hernias (>50%) arise 18 months or more after surgery; they are more common in patients who have avoided exertion for longer periods of time (more than 8 weeks). Our questionnaire was returned by 386 surgical clinics. The responses showed that 78% of recommendations were based on personal experience only. The recommendations varied widely; exertion avoidance was recommended for as long as 6 months.

CONCLUSION

The dilemma of a deficient evidence base for postoperative exertion avoidance to protect the abdominal wall should be resolved with the much higher-quality evidence available from hernia research, which concerns the patient population with the biologically least favorable starting conditions. Based on our analysis of the available literature in light of the biomechanical principles of abdominal wall healing, we propose a new set of recommendations on postoperative exertion avoidance after abdominal surgery, with the goal of eliminating excessively protracted exertion avoidance and enabling a timely return to work.

Selected conditions associated with an increased incidence of incisional hernia: A review of molecular biology

BACKGROUND

Incisional hernias (IH) following a laparotomy, on average, occur in 10-20% of patients, however, little is known about its molecular basis. Thus, a better understanding of the molecular mechanisms could lead to the identification of key target(s) to intervene pre-and post-operatively.

METHODS

We examined the current literature describing the molecular mechanisms of IH and overlap these factors with smoking, abdominal aortic aneurysm, obesity, diabetes mellitus, and diverticulitis.

RESULTS

The expression levels of collagen I and III, matrix metalloproteinases, and tissue inhibitors of metalloproteases are abnormal in the extracellular matrix (ECM) of IH patients and ECM disorganization has an overlap with these comorbid conditions.

CONCLUSION

Understanding the pathophysiology of IH development and associated risk factors will allow physicians to identify patients that may be at increased risk for IH and to possibly act preemptively to decrease the incidence of IH.

Novel understanding of high mobility group box-1 in the immunopathogenesis of incisional hernias

Introduction: Incisional hernias (IH) arise as a complication of patients undergoing laparotomy. Current literature has assessed the role of extracellular matrix (ECM) disorganization, alterations in type I and type III collagen, matrix metalloproteinases, and tissue inhibitors of metalloproteases on IH. However, there is limited information on the underlying molecular mechanisms that lead to ECM disorganization. Areas covered: We critically reviewed the literature surrounding IH and ECM disorganization and offer a novel pathway that may be the underlying mechanism resulting in ECM disorganization and the immunopathogenesis of IH. Expert opinion: High mobility group box-1 (HMGB-1), a damage-associated molecular pattern, plays an important role in the sterile inflammatory pathway and has been linked to ECM disorganization and the triggering of the NLRP3 inflammasome. Further research to investigate the role of HMGB-1 in the molecular pathogenesis of IH would be critical in identifying novel therapeutic targets in the management of IH formation.

Molecular Mechanisms and Potential Therapeutic Targets in Incisional Hernia

The pathophysiology underlying the formation, progression, and surgical healing of incisional hernia (IH) that develops as a major complication associated with abdominal laparotomy is poorly understood. The proposed mechanisms include the switch of collagen phenotype and the proliferation of abnormal fibroblasts after surgery. The focus of this article was to critically review the cellular, biochemical, and potential molecular events associated with the development of IH. The disturbance in collagen homeostasis with alterations in the expression of collagen subtypes, including type 1, type 3, type 4, and type 5, and impairment in the transdifferentiation of fibroblasts to myofibroblasts are discussed. The phenotype switch of wound-repair fibroblasts results in mechanically compromised extracellular matrix that triggers the proliferation of abnormal fibroblasts. High-mobility group box 1 could be involved in wound progression, whereas signaling events mediated by tumor necrosis factor β1, connective tissue growth factor, lysyl oxidase, and hypoxia-inducible factor 1 play significant role in the wound healing response. Thus, the ratio of tumor necrosis factorβ1: high-mobility group box 1 could be a critical determinant of the underlying pathology. Potential target sites for therapeutic intervention in the management of IH are recognized.

The modified laparoscopic keyhole parastomal hernia repair with in situ re-ostomy has low recurrence rate

PURPOSE

This study aimed to present a modified laparoscopic keyhole parastomal hernia repair technique with in situ re-ostomy and show its safety and feasibility at a mid-term follow-up.

METHODS

The technique begins with adhesiolysis during laparoscopy. An annular incision is made between the skin and stomal mucosa. Then, after all adhesions of the stomal bowel and its mesentery are separated from the hernial sac, the stomal bowel is delivered through the keyhole mesh. The mesh is then stitched to the stomal bowel and placed intraperitoneally. The hernial ring is narrowed, and the mesh is further stitched to the hernial ring and stomal tube. After the mesh is fixed, the redundant stomal bowel is shortened, and a new in situ stoma is matured in the conventional way.

RESULTS

Altogether, 65 consecutive patients underwent successful hernia repair via a modified laparoscopic keyhole with in situ re-ostomy. Two of the patients had recurrent parastomal hernias. No mortalities occurred during the perioperative period. Morbidities included two cases of seroma and three of ileus, all of which were cured with conservative treatment. In addition, one case of intestinal perforation was rescued by intestinal resection and enteroenterostomy. Median follow-up was 29 months (range 3-60 months). No complications of mesh-related infection or patch erosion were noted during the follow-up.

CONCLUSIONS

Modified laparoscopic keyhole parastomal hernia repair with in situ re-ostomy is a safe procedure with a low recurrence rate at the mid-term follow-up.

Collagen I and III in women with diastasis recti

OBJECTIVES

Interest in elucidating the etiology of hernias has encouraged countless studies of musculoaponeurotic structures in individuals with and without hernias. Studies of hernia patients have firmly demonstrated a correlation between hernias and collagen alterations in their fascia. Diastasis recti is an increased width of the abdominal midline that is exclusively composed of interlacing aponeurotic expansions of the anterolateral abdominal muscles. The condition is common among women undergoing abdominoplasty, and many factors, not only mechanical, play a role. The goal of this study is to evaluate and compare collagen type I and III levels in the midline fascia of women with and without diastasis recti to report their possible influence on this condition.

METHODS

This is a case-control study nested within a surgical cohort of 18 women with diastasis recti and 18 women without the condition (cases and controls, respectively). Fascia from the midline of the abdominal wall was collected and analyzed through immunohistochemistry using polyclonal antibodies to collagen type I and III.

RESULTS

Both type I and type III collagen were less abundant in women with diastasis recti than in those without the condition, and the difference was statistically significant (p<0.001).

CONCLUSION

Low collagen type I and type III levels in the midline of the abdominal wall may play a key role in the development of diastasis recti.

Stomal Closure: Strategies to Prevent Incisional Hernia

Incisional hernias following ostomy reversal occur frequently. Incisional hernias at the site of a previous stoma closure can cause significant morbidity, impaired quality of life, lead to life-threatening hernia incarceration or strangulation and result in a significant financial burden on health care systems Despite this, the evidence base on the subject is limited. Many recognised risk factors for the development of incisional hernia following ostomy reversal are related to patient factors such as age, malignancy, diabetes, COPD, hypertension and obesity, and are not easily correctable. There is a limited amount of evidence to suggest that prophylactic mesh reinforcement may be of benefit to reduce the post stoma closure incisional hernia rate but a further large scale randomised controlled trial is due to report in the near future. There appears to be weak evidence to suggest that surgeons should favour circular, or "purse-string" closure of the skin following stoma closure in order to reduce the risk of SSI, which in turn may reduce incisional hernia formation. There remains the need for further evidence in relation to suture technique, skin closure techniques, mechanical bowel preparation and oral antibiotic prescription focusing on incisional hernia development as an outcome measure. Within this review, we discuss in detail the evidence base for the risk factors for the development of, and the strategies to prevent ostomy reversal site incisional hernias.

International guidelines for groin hernia management

INTRODUCTION

Worldwide, more than 20 million patients undergo groin hernia repair annually. The many different approaches, treatment indications and a significant array of techniques for groin hernia repair warrant guidelines to standardize care, minimize complications, and improve results. The main goal of these guidelines is to improve patient outcomes, specifically to decrease recurrence rates and reduce chronic pain, the most frequent problems following groin hernia repair. They have been endorsed by all five continental hernia societies, the International Endo Hernia Society and the European Association for Endoscopic Surgery.

METHODS

An expert group of international surgeons (the HerniaSurge Group) and one anesthesiologist pain expert was formed. The group consisted of members from all continents with specific experience in hernia-related research. Care was taken to include surgeons who perform different types of repair and had preferably performed research on groin hernia surgery. During the Group's first meeting, evidence-based medicine (EBM) training occurred and 166 key questions (KQ) were formulated. EBM rules were followed in complete literature searches (including a complete search by The Dutch Cochrane database) to January 1, 2015 and to July 1, 2015 for level 1 publications. The articles were scored by teams of two or three according to Oxford, SIGN and Grade methodologies. During five 2-day meetings, results were discussed with the working group members leading to 136 statements and 88 recommendations. Recommendations were graded as "strong" (recommendations) or "weak" (suggestions) and by consensus in some cases upgraded. In the Results and summary section below, the term "should" refers to a recommendation. The AGREE II instrument was used to validate the guidelines. An external review was performed by three international experts. They recommended the guidelines with high scores. The risk factors for inguinal hernia (IH) include: family history, previous contra-lateral hernia, male gender, age, abnormal collagen metabolism, prostatectomy, and low body mass index. Peri-operative risk factors for recurrence include poor surgical techniques, low surgical volumes, surgical inexperience and local anesthesia. These should be considered when treating IH patients. IH diagnosis can be confirmed by physical examination alone in the vast majority of patients with appropriate signs and symptoms. Rarely, ultrasound is necessary. Less commonly still, a dynamic MRI or CT scan or herniography may be needed. The EHS classification system is suggested to stratify IH patients for tailored treatment, research and audit. Symptomatic groin hernias should be treated surgically. Asymptomatic or minimally symptomatic male IH patients may be managed with "watchful waiting" since their risk of hernia-related emergencies is low. The majority of these individuals will eventually require surgery; therefore, surgical risks and the watchful waiting strategy should be discussed with patients. Surgical treatment should be tailored to the surgeon's expertise, patient- and hernia-related characteristics and local/national resources. Furthermore, patient health-related, life style and social factors should all influence the shared decision-making process leading up to hernia management. Mesh repair is recommended as first choice, either by an open procedure or a laparo-endoscopic repair technique. One standard repair technique for all groin hernias does not exist. It is recommended that surgeons/surgical services provide both anterior and posterior approach options. Lichtenstein and laparo-endoscopic repair are best evaluated. Many other techniques need further evaluation. Provided that resources and expertise are available, laparo-endoscopic techniques have faster recovery times, lower chronic pain risk and are cost effective. There is discussion concerning laparo-endoscopic management of potential bilateral hernias (occult hernia issue). After patient consent, during TAPP, the contra-lateral side should be inspected. This is not suggested during unilateral TEP repair. After appropriate discussions with patients concerning results tissue repair (first choice is the Shouldice technique) can be offered. Day surgery is recommended for the majority of groin hernia repair provided aftercare is organized. Surgeons should be aware of the intrinsic characteristics of the meshes they use. Use of so-called low-weight mesh may have slight short-term benefits like reduced postoperative pain and shorter convalescence, but are not associated with better longer-term outcomes like recurrence and chronic pain. Mesh selection on weight alone is not recommended. The incidence of erosion seems higher with plug versus flat mesh. It is suggested not to use plug repair techniques. The use of other implants to replace the standard flat mesh in the Lichtenstein technique is currently not recommended. In almost all cases, mesh fixation in TEP is unnecessary. In both TEP and TAPP it is recommended to fix mesh in M3 hernias (large medial) to reduce recurrence risk. Antibiotic prophylaxis in average-risk patients in low-risk environments is not recommended in open surgery. In laparo-endoscopic repair it is never recommended. Local anesthesia in open repair has many advantages, and its use is recommended provided the surgeon is experienced in this technique. General anesthesia is suggested over regional in patients aged 65 and older as it might be associated with fewer complications like myocardial infarction, pneumonia and thromboembolism. Perioperative field blocks and/or subfascial/subcutaneous infiltrations are recommended in all cases of open repair. Patients are recommended to resume normal activities without restrictions as soon as they feel comfortable. Provided expertise is available, it is suggested that women with groin hernias undergo laparo-endoscopic repair in order to decrease the risk of chronic pain and avoid missing a femoral hernia. Watchful waiting is suggested in pregnant women as groin swelling most often consists of self-limited round ligament varicosities. Timely mesh repair by a laparo-endoscopic approach is suggested for femoral hernias provided expertise is available. All complications of groin hernia management are discussed in an extensive chapter on the topic. Overall, the incidence of clinically significant chronic pain is in the 10-12% range, decreasing over time. Debilitating chronic pain affecting normal daily activities or work ranges from 0.5 to 6%. Chronic postoperative inguinal pain (CPIP) is defined as bothersome moderate pain impacting daily activities lasting at least 3 months postoperatively and decreasing over time. CPIP risk factors include: young age, female gender, high preoperative pain, early high postoperative pain, recurrent hernia and open repair. For CPIP the focus should be on nerve recognition in open surgery and, in selected cases, prophylactic pragmatic nerve resection (planned resection is not suggested). It is suggested that CPIP management be performed by multi-disciplinary teams. It is also suggested that CPIP be managed by a combination of pharmacological and interventional measures and, if this is unsuccessful, followed by, in selected cases (triple) neurectomy and (in selected cases) mesh removal. For recurrent hernia after anterior repair, posterior repair is recommended. If recurrence occurs after a posterior repair, an anterior repair is recommended. After a failed anterior and posterior approach, management by a specialist hernia surgeon is recommended. Risk factors for hernia incarceration/strangulation include: female gender, femoral hernia and a history of hospitalization related to groin hernia. It is suggested that treatment of emergencies be tailored according to patient- and hernia-related factors, local expertise and resources. Learning curves vary between different techniques. Probably about 100 supervised laparo-endoscopic repairs are needed to achieve the same results as open mesh surgery like Lichtenstein. It is suggested that case load per surgeon is more important than center volume. It is recommended that minimum requirements be developed to certify individuals as expert hernia surgeon. The same is true for the designation "Hernia Center". From a cost-effectiveness perspective, day-case laparoscopic IH repair with minimal use of disposables is recommended. The development and implementation of national groin hernia registries in every country (or region, in the case of small country populations) is suggested. They should include patient follow-up data and account for local healthcare structures. A dissemination and implementation plan of the guidelines will be developed by global (HerniaSurge), regional (international societies) and local (national chapters) initiatives through internet websites, social media and smartphone apps. An overarching plan to improve access to safe IH surgery in low-resource settings (LRSs) is needed. It is suggested that this plan contains simple guidelines and a sustainability strategy, independent of international aid. It is suggested that in LRSs the focus be on performing high-volume Lichtenstein repair under local anesthesia using low-cost mesh. Three chapters discuss future research, guidelines for general practitioners and guidelines for patients.

CONCLUSIONS

The HerniaSurge Group has developed these extensive and inclusive guidelines for the management of adult groin hernia patients. It is hoped that they will lead to better outcomes for groin hernia patients wherever they live. More knowledge, better training, national audit and specialization in groin hernia management will standardize care for these patients, lead to more effective and efficient healthcare and provide direction for future research.

Complications and recurrence rates of patients with Ehlers-Danlos syndrome undergoing ventral hernioplasty: a case series

Purpose

Ventral hernia repair is one of the most frequently performed surgical procedures, though recurrences are common. Recurrence can be caused by impaired collagen formation or maturation; hence, patients with Ehlers-Danlos syndrome (EDS) are potentially at increased risk for hernia recurrence. EDS causes altered collagen metabolism, though little is known about the influence of EDS on ventral hernioplasty outcomes. This study aims to analyze these patients to report complication rates, recurrence rates, and, if possible, to give recommendations for surgical intervention.

Methods

A retrospective analysis between January 2000 and January 2017 was performed in a university hospital Belgium (UZ Ghent). Data on baseline characteristics, primary surgery, and hernias were extracted from patients’ medical charts. Noted endpoints were postoperative complications and recurrences.

Results

Fourteen patients (50% males) were included. Ten (71%) had an incisional hernia and four (29%) had a primary ventral hernia. Median age was 45 years (IQR 37.75–52.75), median BMI was 24.82 (IQR 22.43–26.87). Four patients (29%) smoked, one patient (7.1%) had diabetes mellitus, and five patients (36%) had an aneurysm of the abdominal aorta. All patients underwent elective open hernioplasty with mesh reinforcement. Three patients (21%) had a postoperative complication (two infections, one seroma). Recurrence rate was 7.1% (one patient).

Conclusions

This series describes 14 patients with a median follow-up of 50 months and a recurrence rate of 7.1%. The low recurrence rate could be explained by the use of large meshes that reinforce the entire midline to compensate for the reduced collagen strength in EDS patients.

Metalloproteinases and Their Inhibitors in Patients with Inguinal Hernia

AIM

The aim of this prospective study is to investigate if there is a relationship between inguinal hernia, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs).

MATERIALS AND METHODS

This case control study was performed on patients admitted to the general surgery department of Erzincan University Hospital. Four groups were created: control, indirect hernia, direct hernia, and bilateral hernia. All groups were comprised of 11 patients. Serum and tissue levels of MMP-1, MMP-2, MMP-9, MMP-13, TIMP-1, TIMP-2, TIMP-3, and hydroxyproline were evaluated.

RESULTS

MMPs values were significantly high at hernia groups, especially at bilateral hernia group (p < 0.05), whereas TIMPs values were significantly low at bilateral hernia group (p < 0.05). MMPs values were increasing at hernia groups in an order as control, indirect, direct, and bilateral. TIMPs values were decreasing at hernia groups in an order as control, indirect, direct, and bilateral.

CONCLUSION

Increased levels of MMP-1-2-9-13 and decreased levels of TIMP-1-2-3 may have played role in the formation of inguinal hernia. Hernia is not only a local defect, but a reflection of systemic disease. This is even more significant for bilateral hernias.

Hernias- Is it a primary defect or a systemic disorder? Role of collagen III in all hernias- A case control study

Introduction

The need of this study is to assess the role of collagen III in all hernias which include primary inguinal hernias ventral and recurrent abdominal hernias.

Collagen type III represents the mechanically instable, less cross-linked collagen synthesized during the early days of wound healing. Quantitative assessment of collagen III in scar tissue on transversalis fascia as tissue obtained from cases operated for various hernias and compared to that of patients operated for abdominal surgeries for indications other than hernia was compared.

Materials and methods

In this study we had a total of 90 patients, of which 45 patients underwent mesh repair for the various hernias and 45 patients who underwent laparotomies for various reasons were included as controls. Size of 1 × 1cm transversalis fascia was taken in both subjects and was sent for quantitative assessment using Immunohistochemistry test. All the above cases were randomized as per age,sex,BMI, co morbidities and materials used for repair.

Results

Results were analysed quantitatively and classified into following groups:Based on intensity of staining into Mild, Intermediate and Well stained and based on Quantity of Collagen III into Grade 0---NIL, Grade 1--1-25%, Grade 2-26-50%, Grade 3--51-75%, Grade 4--76-100% (Table 1). In the case group we had 52.4%,35.7% and 11.9% of the cases in Grade 4, Grade 3 and Grade 2 which proved that there was increased presence of Collagen 3, where as 84.4%,4.4% and 11.1% of patients in the control group were classified as Grade 1, Grade 2, Grade 0. For the quantitative study -Chi square test value −81.279 and the p value < 0.001. For the intensity of staining -Chi square test value −57.64 and p value is < 0.001.

Conclusion

This study signifies that ventral, recurrent and primary inguinal hernias are not just caused because of a primary defect but an acquired disorder with respect to collagen distribution.

•

Collagen III.

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Quantitative study.

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Grade and intensity of staining.

Advanced glycation end products as a biomarker for incisional hernia

Background

Incisional hernia is one of the most frequent complications after abdominal surgery, with incidences up to 30%. A reliable biomarker for the prediction of this complication is lacking. Advanced glycosylation end products (AGEs), also known as non-enzymatic collagen crosslinks, are correlated with aging, smoking, hyperglycemia, hyperlipidemia and oxidative stress. In this study the accumulation of AGEs and the relation between AGEs and incisional hernia were investigated.

Materials and methods

In an exploratory case–control study, 23 patients with incisional hernia after midline incision were compared with 17 patients without clinical or radiological signs of incisional hernia after midline incision, AGEs were measured using a Skin Auto Fluorescence (SAF)-reader.

Results

Twenty-three patients with a clinically significant incisional hernia and 17 control patients were included. The study groups had significant differences in mean BMI. There was a significant difference between mean AGEs in patients with and without incisional hernia after midline incision (3.00 ± 0.15 vs. 2.56 ± 0.11, T test p = 0.03).

Conclusion

AGE accumulation measured in the skin indirectly with autofluorescence might be associated with incisional hernia. Prospective larger trials should confirm this finding.

Collagenopathies-Implications for Abdominal Wall Reconstruction: A Systematic Review

Background:

The etiology of hernia formation is strongly debated and includes mechanical strain, prior surgical intervention, abnormal embryologic development, and increased intraabdominal pressure. Although the most common inciting cause in ventral hernias is previous abdominal surgery, many other factors contribute. We explore this etiology through an examination of the current literature and existing evidence on patients with collagen vascular diseases, such as Ehlers–Danlos syndrome.

Methods:

A systematic review of the published literature was performed of all available Spanish and English language PubMed and Cochrane articles containing the key words “collagenopathies,” “collagenopathy,” “Ehlers-Danlos,” “ventral hernia,” and “hernia.”

Results:

Three hundred fifty-two articles were identified in the preliminary search. After review, 61 articles were included in the final review.

Conclusions:

Multiple authors suggest a qualitative or quantitative defect in collagen formation as a common factor in hernia formation. High-level clinical data clearly linking collagenopathies and hernia formation are lacking. However, a trend in pathologic studies suggests a link between abnormal collagen production and/or processing that is likely associated with hernia development.

Stoma Care Problems after Stoma Surgery in Northern Finland

Background and Aims:

Stoma-related complications and problems in stoma care are common after gastrointestinal surgery requiring the construction of a stoma. The frequency and types of such complications and problems were evaluated in a patient cohort operated on in Oulu University Hospital.

Material and Methods:

A detailed questionnaire concerning clinical problems and stoma care was mailed to 163 stoma patients operated on during the years from 1995 to 2001 in Oulu University Hospital. One hundred and nineteen patients (70 percent) answered the questions adequately. The clinical variables concerning stoma complications and the patients' symptoms, problems with stoma care and adaptation to the situation were recorded. Special attention was paid to the patients' general wellbeing and social problems.

Results:

Thirty-five patients (30%) had stoma complications, most commonly parastomal hernias (18 cases). Patients with an ileostomy had more difficulties with stoma handling more often than the patients with a colostomy. Seventy-eight patients (66%) were well adapted to their stoma, including 49 (72%) of the patients with a colostomy and 25 (56%) of the patients with an ileostomy. Of the 41 non-adapted patients, 12 did not accept their altered body image, ten had problems in social life and nine had difficulties because of faecal leakage. The quality of life analysis of 114 patients showed that their physical condition was better than before the operation in 55 cases (48%), unchanged in 16 (14%) and worse in 43 (38%). General mental health was better than before the operation in 52 cases (46%), unchanged in 23 (20%) and worse in 39 (34%) patients. Social functioning had improved after stoma surgery in 38 cases (34%), remained unchanged in 27 (24%) and deteriorated in 46 (42%) patients after stoma surgery. Patients with a colostomy reported worse subjective physical condition, mental health and social functioning than the patients with an ileostomy.

Conclusions:

Two-thirds of the patients had adapted to their stoma. The patients with an ileostomy had difficulties in stoma handling and the patients with a colostomy reported their physical, mental and social wellbeing to be affected.

Experimental study of inflammatory response and collagen morphometry with different types of meshes

PURPOSE

To compare an inflammation score and collagen morphometry after incisional hernia repair with four different meshes at two time points.

METHODS

Four types of mesh were used to repair an abdominal wall incisional defect in Wistar rats: high-density polypropylene (HW/PP); low-density polypropylene (LW/PP); polypropylene mesh encapsulated with polydioxanone coated with oxidized cellulose (PP/CE); and expanded polytetrafluoroethylene (ePTFE). An inflammation score based on histological analysis and collagen morphometry was performed after 7 and 28 days after operation (POD).

RESULTS

Compared to LW/PP group at 7 POD, HW/PP group had lower (p = 0.014) and PP/CE group had higher inflammation scores (p = 0.001). At 28 POD, higher scores were seen in all the other groups compared to the LW/PP group (HW/PP, p = 0.046; PP/CE, p < 0.001; ePTFE, p = 0.027). Comparing groups individually at 7 and 28 PODs, all demonstrated lower inflammation score values at 28 POD (HW/PP, p < 0.001; LW/PP, p < 0.001; PP/CE, p = 0.002; ePTFE, p = 0.001). At 7 POD, higher amounts of collagen were detected in ePTFE compared to HW/PP (p < 0.001) and LW/PP (p = 0.004) and in PPCE group compared to HW/PP (p = 0.022). At 28 POD, no statistically significant difference was found. Comparing groups individually at 7 and 28 PODs, HW/PP and LW/PP showed larger amounts of collagen at the 28th POD, without any statistically significant differences for the PP/CE and ePTFE groups.

CONCLUSIONS

Inflammation scores decreased in all groups at 28 POD. Collagen deposition was higher for non-composite meshes at 28 POD.

Abdominal wall hernias-A local manifestation of systemically impaired quality of the extracellular matrix

BACKGROUND

Throughout life, inguinal hernia develops in approximately every fourth man, some of whom develop multiple hernias. If patients at risk of developing multiple hernias could be identified by a serologic biomarker, treatment might be able to be tailored and improved. Evidence suggests that abdominal wall hernia formation is associated with altered collagen metabolism. The aim of this study was to evaluate biomarkers for type IV and V collagen turnover in patients with multiple hernias and control subjects without hernia.

METHODS

Venous blood was collected from 88 men (mean age, 62 years) with a history of more than 3 hernia repairs and 86, age-matched men without hernias. Biomarkers for synthesis of collagen type IV (P4NP) and type V (P5CP) as well as breakdown (C4M and C5M) were measured in serum by validated, solid-phase, competitive assays. Collagen turnover was indicated by the ratio between the biomarker for synthesis and breakdown.

RESULTS

Type IV collagen turnover was 1.4-fold increased in patients with multiple hernias compared to control subjects (P < .001), whereas type V collagen turnover was 1.7-fold decreased (P < .001). Diagnostic power of P5CP was 0.83 (95%C.I.:0.77-0.89), P < .001.

CONCLUSION

Patients with multiple hernias exhibit increased turnover of type IV collagen and a decreased turnover of type V collagen, demonstrating systemically altered collagen turnover. Biomarkers for type V collagen turnover may be used to identify patients at risk for or with multiple hernias.

A pancreaticoduodenal artery aneurysm

A 70-year-old man was investigated with CT imaging for haematuria. An incidental finding was made of a large inferior pancreaticoduodenal artery aneurysm. Following a period of monitoring, the patient underwent open repair of the aneurysm. This case report highlights an unusual pathology and discusses the clinical complexities related to its management.

Tamoxifen induces the development of hernia in mice by activating MMP-2 and MMP-13 expression

Hernia is a disease with defects in collagen synthesis/metabolism. However, the underlying mechanisms for hernia formation have not been fully defined. Tamoxifen is a selective estrogen receptor modulator and used for patients with breast cancer. Tamoxifen also has pleiotropic and side effects. Herein, we report that tamoxifen treatment resulted in an appearance of a large bulge in the low abdomen between the hind legs in male but not in female mice. The autopsy demonstrated that the low abdominal wall was broken and a large amount of intestine herniated out of the abdominal cavity. Histological analysis indicated that tamoxifen caused structural abnormalities in the low abdominal wall which were associated with decreased type II collagen content. Furthermore, we determined increased matrix metalloproteinase-2 (MMP-2) and MMP-13 expression in the tissue. In vitro, tamoxifen induced MMP-2 and MMP-13 expression in fibroblasts. The promoter activity analysis and ChIP assay demonstrate that induction of MMP-13 expression was associated with activation of JNK-AP-1 and ERK1/2 signaling pathways while induction of MMP-2 expression was related to activation of the ERK1/2 signaling pathway. Taken together, our study establishes a novel murine hernia model, defines a severe side effect of tamoxifen, and suggests a caution to male patients receiving tamoxifen treatment.

Laparoscopic ventral hernia repair: outcomes in primary versus incisional hernias: no effect of defect closure

PURPOSE

Supposing divergent aetiology, we found it interesting to investigate outcomes between primary (PH) versus incisional (IH) hernias. In addition, we wanted to analyse the effect of defect closure and mesh fixation techniques.

METHODS

37 patients with PH and 70 with IH were enrolled in a prospective cohort-study, treated with laparoscopic ventral hernia repair (LVHR) and randomised to ± transfascial sutures. In addition, we analysed results from a retrospective study with 36 PH and 51 IH patients. Mean follow-up time was 38 months in the prospective study and 27 months in the retrospective study.

RESULTS

35 % of PH's and 10 % of IH's were recurrences after previous suture repair. No late infections or mesh removals occurred. Recurrence rates in the prospective study were 0 vs. 4.3 % (p = 0.55) and the complication rates were 16 vs. 27 % (p = 0.24) in favour of the PH cohort. The IH group had a mesh protrusion rate of 13 vs. 5 % in the PH group (p = 0.32), and significantly (p < 0.01) larger hernias and adhesion score, longer operating time (100 vs. 79 min) and admission time (2.8 vs. 1.6 days). Closure of the hernia defect did not influence rate of seroma, pain at 2 months, protrusion or recurrence. An overall increased complication rate was seen after defect closure (OR 3.42; CI 1.25-9.33).

CONCLUSIONS

With PH, in comparison to IH treated with LVHR, no differences were observed regarding recurrence, protrusion or complication rates. Defect closure (raphe), when using absorbable suture, did not benefit long-term outcomes and caused a higher overall complication rate. (ClinicalTrials.gov number: NCT00455299).

Effects of Blocking αvβ₃ integrin by a recombinant RGD disintegrin on remodeling of wound healing after induction of incisional hernia in rats

PURPOSE

Incisional hernia (IH) is characterized by defective wound healing process. Disba-01, a αvb₃ integrin blocker has shown to control the rate of wound repair and therefore it could be a target for new wound healing therapies.The objective of the study was to determine the changes induced by Disba-01 on repair of wound healing after induced IH in rats.

METHODS

Thirty two male albino rats were submitted to IH and divided into 4 experimental groups: G1, placebo control; G2, DisBa-01-treated; G3, anti-αvβ₃ antibodies-treated and G4, anti-α₂ antibodies-treated. Histological. biochemical and extracellular matrix remodeling analysis of abdominal wall were evaluated.

RESULTS

After 14 days, 100% of the G2 did not present hernia, and the hernia ring was closed by a thin membrane. In contrast, all groups maintained incisional hernia. DisBa-01 also increased the number macrophages and fibroblasts and induced the formation of new vessels. Additionally, MMP-2 was strongly activated only in G2 (P<0.05). Anti- αvβ₃-integrin antibodies produced similar results than Disba-01 but not anti-α₂ integrin blocking antibodies.

CONCLUSION

These results strongly indicate that Disba-01 has an important role in the control of wound healing and the blocking of this integrin may be an interesting therapeutical strategy in IH.

Measurement of hydroxyproline and nitric oxide, and comparison of sac fluid acidity in different inguinal pathologies

PURPOSE

To compare hydroxyproline and nitric oxide levels, and fluid acidity between sac tissues from inguinal hernia, hydrocele and undescended testis patients.

MATERIAL AND METHOD

Thirty patients were in the inguinal hernia group, 11 patients in the hydrocele group and 5 patients in the undescended testis with inguinal hernia group. Intrasaccular fluid acidity, and nitric oxide and hydroxyproline levels in sac tissues were measured and analyzed statistically between groups.

RESULTS

Intrasaccular fluid could be obtained from 24 inguinal hernia and 6 hydrocele patients. Acidity level (pH) was 7.5 ± 0.74 in the hernia group and 7.86 ± 0.63 in the hydrocele group (p < 0.05). All patients in the three groups were evaluated for nitric oxide and hydroxyproline. Results for hydroxyproline (mg/g dry tissue)/nitric oxide (nmol/g wet tissue) were 3.53 ± 0.54/2.02 ± 0.39 for inguinal hernia, 2.89 ± 0.9/1.92 ± 1.05 for hydrocele and 3.02 ± 1.23/2.86 ± 1.09 for undescended testis group (p > 0.05).

CONCLUSION

Hydroxyproline and nitric oxide pathways do not seem to be responsible for the different characteristics of inguinal diseases. However, differences in the acidity of sac fluid may be evidence of the different mechanisms of hernia and hydrocele formation.

Circulating levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in patients with incisional hernia

Incisional hernia formation is a common complication to laparotomy and possibly associated with alterations in connective tissue metabolism. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are closely involved in the metabolism of the extracellular matrix. Our aim was to study serum levels of multiple MMPs and TIMPs in patients with and without incisional hernia. Out of 305 patients who underwent laparotomy, 79 (25.9%) developed incisional hernia over a median follow-up period of 3.7 years. Pooled sera from a subset (n = 72) of these patients were screened for MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-10, MMP-12, MMP-13, TIMP-1, TIMP-2, and TIMP-4 using a multiplex sandwich fluorescent immunoassay supplemented with gelatin zymography. The screening indicated differences in serum MMP-9 and TIMP-1 levels. Consequently, MMP-9 and TIMP-1 levels were measured in serum in the whole patient cohort with enzyme-linked immunosorbent assay. There were no significant differences in either MMP-9 (p = 0.411) or TIMP-1 (p = 0.679) levels between hernia and hernia-free patients. MMP-9 was significantly increased in smokers compared with nonsmokers (p = 0.016). In conclusion, a possible involvement of MMPs and TIMPs in the pathogenesis of incisional hernia formation was not reflected systemically.

Direct and recurrent inguinal hernias are associated with ventral hernia repair: a database study

BACKGROUND

A systemically altered connective tissue metabolism has been demonstrated in patients with abdominal wall hernias. The most pronounced connective tissue changes are found in patients with direct or recurrent inguinal hernias as opposed to patients with indirect inguinal hernias. The aim of the present study was to assess whether direct or recurrent inguinal hernias are associated with an elevated rate of ventral hernia surgery.

METHODS

In the nationwide Danish Hernia Database, a cohort of 92,457 patients operated on for inguinal hernias was recorded from January 1998 until June 2010. Eight-hundred forty-three (0.91 %) of these patients underwent a ventral hernia operation between January 2007 and June 2010. A multivariate logistic regression analysis was applied to assess an association between inguinal and ventral hernia repair.

RESULTS

Direct (Odds Ratio [OR] = 1.28 [95 % CI, 1.08-1.51]) and recurrent (OR = 1.76, [95 % CI, 1.39-2.23]) inguinal hernias were significantly associated with ventral hernia repair after adjustment for age, gender, and surgical approach (open or laparoscopic).

CONCLUSIONS

Patients with direct and recurrent inguinal herniation are more prone to ventral hernia repair than patients with indirect inguinal herniation. This is the first study to show that herniogenesis is associated with type of inguinal hernia.

Skin as marker for collagen type I/III ratio in abdominal wall fascia

PURPOSE

An altered collagen metabolism could play an important role in hernia development. This study compared collagen type I/III ratio and organisation between hernia and control patients, and analysed the correlation in collagen type I/III ratio between skin and abdominal wall fascia.

METHODS

Collagen organisation was analysed in Haematoxylin-Eosin sections of anterior rectus sheath fascia, and collagen type I/III ratio, by crosspolarisation microscopy, in Sirius-Red sections of skin and anterior rectus sheath fascia, of 19 control, 10 primary inguinal, 10 recurrent inguinal, 13 primary incisional and 8 recurrent incisional hernia patients.

RESULTS

Compared to control patients [7.2 (IQR = 6.8-7.7) and 7.2 (IQR = 5.8-7.9)], collagen type I/III ratio was significantly lower in skin and anterior rectus sheath fascia of primary inguinal [5.2 (IQR = 3.8-6.3) and 4.2 (IQR = 3.8-4.7)], recurrent inguinal [3.2 (IQR = 3.1-3.6) and 3.3 (IQR = 3-3.7)], primary incisional [3.5 (IQR = 3-3.9) and 3.4 (IQR = 3.3-3.6)] and recurrent incisional hernia [3.2 (IQR = 3.1-3.9) and 3.2 (IQR = 2.9-3.2)] patients; also incisional and recurrent inguinal hernia had lower ratio than primary inguinal hernia patients. Furthermore, collagen type I/III ratio was significantly correlated (r = 0.81; P < 0.001) between skin and anterior rectus sheath fascia. Finally, collagen organisation was comparable between hernia and control patients.

CONCLUSIONS

Furthermore, in both skin and abdominal wall fascia of hernia patients, collagen type I/III ratio was lower compared to control patients, with more pronounced abnormalities in incisional and recurrent inguinal hernia patients. Importantly, collagen type I/III ratio in skin was representative for that in abdominal wall fascia.

The INCH-Trial: a multicentre randomized controlled trial comparing the efficacy of conventional open surgery and laparoscopic surgery for incisional hernia repair

BACKGROUND

Annually approximately 100.000 patients undergo a laparotomy in the Netherlands. About 15,000 of these patients will develop an incisional hernia. Both open and laparoscopic surgical repair have been proven to be safe. However, the most effective treatment of incisional hernias remains unclear. This study, the 'INCH-trial', comparing cost-effectiveness of open and laparoscopic incisional hernia repair, is therefore needed.

METHODS/DESIGN

A randomized multi-center clinical trial comparing cost-effectiveness of open and laparoscopic repair of incisional hernias. Patients with a symptomatic incisional hernia, eligible for laparoscopic and open incisional hernia repair. Only surgeons, experienced in both open and laparoscopic incisional hernia repair, will participate in the INCH trial. During incisional hernia repair, a mesh is placed under or on top of the fascia, with a minimal overlap of 5 cm. Primary endpoint is length of hospital stay after an incisional hernia repair. Secondary endpoints are time to full recovery within three months after index surgery, post-operative complications, recurrences, mortality and quality of life.Our hypothesis is that laparoscopic incisional hernia repair comes with a significant shorter hospital stay compared to open incisional hernia repair. A difference of two days is considered significant. One-hunderd-and-thirty-five patients are enrolled in each treatment arm. The economic evaluation will be performed from a societal perspective. Primary outcomes are costs per patient related to time-to-recovery and quality of life.The main goal of the trial is to establish whether laparoscopic incisional hernia repair is superior to conventional open incisional hernia repair in terms of cost-effectiveness. This is measured through length of hospital stay and quality of life. Secondary endpoints are re-operation rate due to post-operative complications or recurrences, mortality and quality of life.

DISCUSSION

The difference in time to full recovery between the two treatment strategies is thought to be in favor of laparoscopic incisional hernia repair. Laparoscopic incisional hernia repair is therefore expected to be a more cost-effective approach.

TRIAL REGISTRATION

Netherlands Trial register: NTR2808.

Incisional hernia recurrence through genomic profiling: a pilot study

PURPOSE

Although situational risk factors for incisional hernia formation are known, the methods used to determine who would be most susceptible to develop one are unreliable. We hypothesized that patients with recurrent incisional hernias may possess unique gene expression profiles.

METHODS

Skin and intact fascia were collected from 15 normal control (NC) patients with no hernia history and 18 patients presenting for recurrent incisional hernia (RH) repair. Microarray analysis was performed using whole genome microarray chips on NC (n = 8) and RH (n = 9). These samples were further investigated using a pathway-specific PCR array containing fibrosis-related genes.

RESULTS

Microarray data revealed distinct differences in the gene expression profiles between RH and NC patients. One hundred and sixty-seven genes in the skin and 7 genes in the fascia were differentially expressed, including 8 directly involved in collagen synthesis. In particular, GREMLIN1, or bone morphogenetic protein antagonist 1, was under expressed in skin (fold = 0.49, p < 10(-7), q = 0.0009) and fascia (fold = 0.23, p < 10(-4), q = 0.095) of RH patients compared with NC. The PCR array data supported previous reports of decreased collagen I/III ratios in skin of RH versus NC (mean = 1.51 ± 0.73 vs. mean = 2.26 ± 0.99; one-sided t test, p = 0.058).

CONCLUSION

To our knowledge, this is the first microarray-based analysis to show distinct gene expression profiles between the skin and fascia of RH and NC patients and the first report of an association between GREMLIN1 and incisional hernia formation. Our results suggest that gene expression profiles may act as surrogate markers that stratify patients into different groups at risk for hernia development prior to their initial surgery.

Abdominal aortic aneurysm and abdominal wall hernia as manifestations of a connective tissue disorder

BACKGROUND

Abdominal aortic aneurysms (AAAs) and abdominal wall hernias represent chronic degenerative conditions. Both aortic aneurysms and inguinal hernias share common epidemiologic features, and several investigators have found an increased propensity for hernia development in patients treated for aortic aneurysms. Chronic inflammation and dysregulation in connective tissue metabolism constitute underlying biological processes, whereas genetic influences appear to be independently associated with both disease states. A literature review was conducted to identify all published evidence correlating aneurysms and hernias to a common pathology.

METHODS

PubMed/Medline was searched for studies investigating the clinical, biochemical, and genetic associations of AAAs and abdominal wall hernias. The literature was searched using the MeSH terms "aortic aneurysm, abdominal," "hernia, inguinal," "hernia, ventral," "collagen," "connective tissue," "matrix metalloproteinases," and "genetics" in all possible combinations. An evaluation, analysis, and critical overview of current clinical data and pathogenic mechanisms suggesting an association between aneurysms and hernias were undertaken.

RESULTS

Ample evidence lending support to the clinical correlation between AAAs and abdominal wall hernias exists. Pooled analysis demonstrated that patients undergoing aortic aneurysm repair through a midline abdominal incision have a 2.9-fold increased risk of developing a postoperative incisional hernia compared with patients treated for aortoiliac occlusive disease (odds ratio, 2.86; 95% confidence interval, 1.97-4.16; P < .00001), whereas the risk of inguinal hernia was 2.3 (odds ratio, 2.30; 95% confidence interval, 1.52-3.48; P < .0001). Emerging evidence has identified inguinal hernia as an independent risk factor for aneurysm development. Although mechanisms of extracellular matrix remodeling and the imbalance between connective tissue degrading enzymes and their inhibitors instigating inflammatory responses have separately been described for both disease states, comparative studies investigating these biological processes in aneurysm and hernia populations are scarce. A genetic predisposition has been documented in familial and observational segregation studies; however, the pertinent literature lacks sufficient supporting evidence for a common genetic basis for aneurysm and hernia.

CONCLUSIONS

Insufficient data are currently available to support a systemic connective tissue defect affecting the structural integrity of the aortic and abdominal wall. Future investigations may elucidate obscure aspects of aneurysm and hernia pathophysiology and create novel targets for pharmaceutical and gene strategies for disease prevention and treatment.

Pelvic organ prolapse and collagen-associated disorders

Introduction and hypothesis

Pelvic organ prolapse (POP) and other disorders, such as varicose veins and joint hypermobility, have been associated with changes in collagen strength and metabolism. We hypothesized that these various disorders were more prevalent in both POP patients and their family members.

Methods

In this study, the prevalence of various collagen-associated disorders, including POP, was compared between POP patients (n = 110) and control patients (n = 100) and their first and second degree family members.

Results

POP patients reported a higher prevalence of varicose veins, joint hypermobility and rectal prolapse and were more likely to have family members with POP as compared to the control group (p < 0.01). In contrast, the family members of the POP group did not report a higher prevalence of collagen-associated disorders compared to the family members of the control group (p = 0.82).

Conclusions

POP and other collagen-associated disorders may have a common aetiology, originating at the molecular level of the collagens.

Hernia recurrence as a problem of biology and collagen

Usually an abdominal wall hernia is regarded as a mechanical problem with a local defect which has to be closed by technical means. Despite the introduction of several therapeutic improvements, recurrent hernias still appear in 10-15%. Therefore, reasons for a recurrence are discussed in a more fundamental way. It is assumed that a failure mainly depends on the quality of the repair. Correspondingly, in principle, the close causal relationship between the technical component and its failure during time is reflected by an s-shaped outcome curve. In contrast, the configuration of the outcome curve changes markedly if a breakdown is caused by numerous components. Then, the superposition of all incidence curves inevitably leads to a linear decline of the outcome curve without any s-shaped deformation. Regarding outcome curves after hernia repair, the cumulative incidences for recurrences of both incisional and inguinal hernia show a linear rise over years. Considering the configuration of outcome curves of patients with hernia disease, it may therefore be insufficient to explain a recurrence just by a failing technical repair. Rather, biological reasons should be suspected, such as a defective wound healing with impaired scarring process. Recent molecular-biological findings provide increasing evidence of underlying biochemical alterations in patients with recurrent hernia. Until predicting markers to identify patients with an impaired wound healing are available and considering the formation of insufficient scar as the underlying disease, the consequences for every surgical repair should be a supplementary reinforcement with nonabsorbable alloplastic nets as flat meshes with an extensive overlap.

The value of copper and zinc levels in hernia formation

BACKGROUND

A defect in collagen metabolism is suspected to be one of the factors responsible for hernia formation. Lysyl oxidase is a copper-dependent enzyme in the process that provides for the structural integrity of collagen molecules, while zinc is essential for tissue maintenance.

MATERIALS AND METHODS

In a prospective fashion, copper and zinc levels were measured in plasma and tissue specimens obtained from indirect (n=23), direct (n=20) and incisional hernia patients (n=19) and from healthy controls (laparoscopic cholecystectomy patients, n=15) by enzymatic colorimetric analysis.

RESULTS

Groups were similar in age, comorbid diseases and body mass index. Whereas plasma levels of Cu and Zn in hernia and control patients were similar, and tissue levels were significantly lower in all hernia groups (especially the incisional hernia group) compared to controls (P<0·001). The incisional hernia group had significantly lower tissue copper levels than direct hernia patients and lower zinc levels than indirect hernia patients.

CONCLUSIONS

Patients with all types of hernia, especially those with incisional hernias, have significantly lower tissue copper and zinc levels than control patients, despite having similar plasma levels. This finding might reflect excessive consumption or dysfunction of lysyl oxidase as playing a role in the aetiology of hernias.

Connective tissue alteration in abdominal wall hernia

BACKGROUND

The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdominal wall hernia formation.

METHODS

A computer-assisted search of the medical databases PubMed and Embase was performed, together with a cross-reference search of eligible papers.

RESULTS

Fifty-two papers were included. Collagen alteration depended on the type of hernia; there were more pronounced changes in patients with a direct inguinal hernia than in those with an indirect inguinal hernia, recurrent inguinal hernia or incisional hernia. A consistent finding was a significant increase in immature type III collagen relative to the stronger type I collagen in patients with a hernia. This resulted in thinner collagen fibres with a correspondingly diminished biomechanical strength. It has been suggested that these alterations are due to variation in the synthesis, maturation or degradation of collagen by matrix metalloproteinases, in combination or alone.

CONCLUSION

Hernia formation and recurrence is associated with altered collagen metabolism manifested by a decreased type I:III collagen ratio.

Randomized clinical trial comparing polypropylene or polydioxanone for midline abdominal wall closure

BACKGROUND

Incisional hernia is a frequent complication of abdominal surgery, often requiring surgical intervention. This prospective randomized trial compared suture materials for closure of the fascia after abdominal surgery.

METHODS

In 456 patients the abdominal fascia was closed with either non-absorbable (polypropylene; Prolene(®)) or absorbable (polydioxanone; PDS(®)) suture material. Follow-up was by clinical examination and ultrasonography at 6-month intervals. Outcome measures were incisional hernia, surgical-site infection and suture sinus.

RESULTS

Some 223 patients were analysed after closure with Prolene(®) and 233 after PDS(®) . Median follow-up was 32 and 31 months respectively. There was no significant difference in the incidence of incisional hernia between the groups: 20·2 per cent (45 of 223) for Prolene(®) and 24·9 per cent (58 of 233) with PDS(®) (P = 0·229). Kaplan-Meier analysis showed a cumulative rate after 4 years of 23·7 and 30·2 per cent for Prolene(®) and PDS(®) respectively (P = 0·222). Secondary outcome measures showed no significant differences.

CONCLUSION

The incidence of incisional hernia in both groups was higher than expected from previous literature. There were no significant differences between the two suture methods.

REGISTRATION NUMBER

ISRCTN65599814 (http://www.clinical-trials.com).

Active matrix metalloproteinase-2 upregulation in the abdominal skin of patients with direct inguinal hernia

BACKGROUND

Prior studies suggest impaired collagen metabolism involving the whole abdominal wall including the skin in patients with abdominal hernia. We compared expression patterns of matrix metalloproteinase-2 (MMP-2) and its modulators membrane type-1-matrix metalloproteinase (MT-1 MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in the skin of patients with and without primary inguinal hernia.

MATERIALS AND METHODS

Skin biopsy specimens from abdominal wall incisions were obtained during surgery from patients with direct inguinal hernia, indirect inguinal hernia or without hernia (controls). MMP-2, MT-1 MMP and TIMP-2 expression were determined using immunocytochemistry and immunoblotting in intact tissue and in cultured fibroblasts isolated from the biopsies. The degradation activity of MMP-2 was semiquantitatively determined using zymography.

RESULTS

Significantly greater active MMP-2 expression was observed in skin fibroblasts obtained from patients with direct hernia compared with controls. MT1-MMP expression was directly correlated with MMP-2 expression with most intense staining produced in patients with direct or indirect inguinal hernia. TIMP-2, was maximally expressed in the control group, with significantly diminished expression levels recorded in the hernia groups.

CONCLUSIONS

Our findings indicate active MMP-2 upregulation in the abdominal skin of patients with direct inguinal hernia. This metalloproteinase plays a role in matrix degradation, weakening the abdominal wall. Skin disorders and previously described transversalis fascia defects in these patients could point to a systemic collagen metabolism abnormality as a risk factor for direct hernia.

Collagen type I:III ratio of the gastroesophageal junction in patients with paraesophageal hernias

BACKGROUND

The purpose of this study was to examine the biological environment of the esophageal hiatus through analysis of the collagen content within the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) in patients with type I hiatal hernias (HH) and type III paraesophageal hernias (PEH).

METHODS

A control group (N=10) and patients with type I HH (N=10) and type III PEH (N=10) were included in the analysis. Specimens of the GHL, PEL, and GPL were collected intraoperatively. Slides stained with sirius red/fast green were created and ten photos at 400×magnification were taken of each specimen. Axiovision 4.7 (Zeiss) photo analysis software was employed for quantification of collagen I (red) and III (green) by calculating color area (μm2). Statistical significance (p<0.05) was determined using a one-way ANOVA and Fisher's LSD post-test.

RESULTS

Cross-polarization microscopy revealed that the collagen I content was similar in the three study groups for the GHL, greater in the type III PEH group and in the control group compared to the type I HH group for the PEL, and greater in the type III PEH group compared to control group for the GPL. Collagen III quantity was greater in the control group than in the type I HH group for each ligament, and greater in the GHL and PEL when compared to the type III PEH group. Type III PEH patients had greater collagen III quantity than did type I HH patients for each ligament. Collagen type I:III ratio of the GHL was greater in both hernia groups compared to the control group. Type III PEH patients contained a higher I:III ratio than both the control and type I HH groups with respect to the PEL. There was no difference in the ratio with evaluation of the GPL for the three groups.

CONCLUSION

Evaluation of the esophageal hiatus revealed that patients with PEH have a different biological environment with regard to collagen content compared to control patients. The collagen I:III ratio of the study groups was equal to or greater than the control group. Collagen deficiency in the GE junction supporting ligaments does not appear to be an etiology of PEH formation.

Laparoscopic parastomal hernia repair

Parastomal hernia is a common complication after stoma formation. Its reported incidence varies from 30% to 50%. Loop ileostomy has the lowest risk (0%-6.2%), followed by end ileostomy, and loop colostomy with a similar risk of 28% to 30%. End colostomy carries the highest risk for parastomal hernia of 48%. Even though most hernias occur within the first 2 years after stoma construction, the risk of herniation extends up to 20 years. Theoretically, parastomal hernia occurs as a result of mechanical factors, an intrinsic defect in collagen metabolism, and wound repair. Parastomal hernia is asymptomatic most of the time, but it may be associated with serious complications such as strangulation and perforation; hence, elective repair is mandatory for carefully selected cases and surgical approaches. Primary closure of the aponeurosis at the hernia site, either via peristomal approach or through midline incision, is a simple procedure, but it carries a recurrence rate of 38% to 100%. Stoma relocation may result in a zero recurrence rate at the same hernia site, but the risk of a parastomal hernia after new stoma formation is still expected. In addition, an incisional hernia at the previous colostomy site closure may also occur. Similar to other sites of hernia repair, prosthetic mesh has been used to reinforce the hernia defect intraperitoneally through open incision and recently via the laparoscopic approach. Mesh repair has demonstrated the lowest risk of recurrence for parastomal hernia of 0% to 33%.

Collagen and elastic content of abdominal skin after surgical weight loss

BACKGROUND

Collapsed skin folds after bariatric weight loss are often managed by plastic procedures, but changes in dermal composition and architecture have rarely been documented. Given the potential consequences on surgical outcome, a prospective histochemical study was designed. The hypothesis was that a deranged dermal fiber pattern would accompany major changes in adipose tissue.

METHODS

Female surgical candidates undergoing postbariatric abdominoplasty (n=40) and never obese women submitted to control procedures (n=40) were submitted to double abdominal biopsy, respectively in the epigastrium and hypogastrium. Histomorphometric assessment of collagen and elastic fibers was executed by the Image Analyzer System (Kontron Electronic 300, Zeiss, Germany).

RESULTS

Depletion of collagen, but not of elastic fibers, in cases with massive weight loss was confirmed. Changes were somewhat more severe in epigastrium (P=0.001) than hypogastrium (P=0.007). Correlation with age did not occur.

CONCLUSIONS

(1) Patients displayed lax, soft skin lacking sufficient collagen fiber network. (2) Elastic fiber content was not damaged, and was even moderately increased in epigastrium; (3) Preoperative obesity negatively correlated with hypogastric collagen concentration; (4) Future studies should pinpoint the roles of obesity, and especially of massive weight loss, on dermal architecture and response to surgery.